An organic thin film transistor (OTFT) is a logic unit device using an organic semiconductor as an active layer, has advantages of being adaptable for large-scale processing, being applicable for flexible substrates, low process cost, etc., and possesses application prospects in the fields of flat panel display, sensor, storage card, radio frequency identification tag, etc. Thus, research and development on organic thin film transistors have gotten great international attentions.
In the prior art, an organic thin film transistor array substrate is usually produced by using a patterning process. It is necessary that a mask pattern should be transferred into a thin film pattern in each patterning process, and each pattern layer should be precisely overlapped with another layer of thin film pattern. At present, five patterning processes are generally needed to produce an organic thin film transistor array substrate. Thus, the number of the used mask is larger, the production efficiency is lower, and the production cost is higher.